To find the number of moles of chlorine needed to form 14 moles of iron (III) chloride (FeCl₃), we can use the balanced chemical equation:
\[ 2 \text{Fe} + 3 \text{Cl}_2 \rightarrow 2 \text{FeCl}_3 \]
From the equation, we can see the stoichiometry between FeCl₃ and Cl₂:
- 2 moles of FeCl₃ are formed from 3 moles of Cl₂.
This means that for every 2 moles of FeCl₃, we need 3 moles of Cl₂. We can set up a ratio to find the number of moles of Cl₂ needed for 14 moles of FeCl₃:
\[ \frac{3 \text{ moles Cl}_2}{2 \text{ moles FeCl}_3} = \frac{x \text{ moles Cl}_2}{14 \text{ moles FeCl}_3} \]
Now, we can solve for \( x \):
\[ x = 14 \text{ moles FeCl}_3 \times \frac{3 \text{ moles Cl}_2}{2 \text{ moles FeCl}_3} \]
Calculating this gives:
\[ x = 14 \times \frac{3}{2} = 14 \times 1.5 = 21 \]
Thus, 21 moles of chlorine (Cl₂) are needed to form 14 moles of iron (III) chloride (FeCl₃).